Rh(III)-Catalyzed Dual C–H Functionalization/Cyclization Cascade by a Removable Directing Group: A Method for Synthesis of Polycyclic Fused Pyrano[<i>de</i>]Isochromenes

Abstract

An interesting Rh(III)-catalyzed dual C-H functionalization/cyclization cascade of azomethine imine with diazophosphonate by a removable directing group for the synthesis of highly fused pyrano[<i>de</i>]isochromene has been achieved. The transformation shows that the desired pyrano[<i>de</i>]isochromenes with two oxygen atoms on its core scaffold could be constructed with good to excellent yields (up to 86%) <i>via</i> a facile one-pot, multiple-step cascade reaction, along with broad generality and versatility.